Innovations in Copper Mineral Processing Technology

Transcription

1 Innovations in Copper Mineral Processing Technology Peter Rohner Core Resources, Brisbane 17 th June 2014

2 Company Overview Highlights Specialist Metallurgical services: hrltesting (metallurgical laboratory operating over 30 years). Marketing of licensed processing technology (Albion Process and Toowong Process). Process engineering, design and flowsheet development Scoping and Feasibility Studies Technology Development Partner Strong Technical Team (~50 Staff): Grinding, flotation and hydrometallurgical expertise Flowsheet development with an economic focus and outcomes that can be engineered and operated Project development, commissioning and operational experience

3 Mineral Processing Technologies Update on Copper Applications using; Ore Sorting Heavy Medium Separation Toowong Process Albion Process Rejecting Low Grade Material from Copper Ores Rejecting Low Grade Material from Copper Ores Removing Impurities from Copper Concentrates Treating Low grade/dirty Copper Concentrates

4 Definition of a Metallurgist met al lur gist (mtl-ûrjst) > A pseudo scientist, who uses undetermined suppositions, inexpressible hypotheses; which are based on unreliable information, uncertain quantities, and incomplete data; derived from non-reproducible experiments and incomplete investigations; using equipment and instruments of questionable accuracy, insufficient resolution, and inadequate sensitivity, to arrive at timid, tentative, cloudy, abstruse, and non-committed conclusions prefaced by the phrase IT DEPENDS

5 Copper Processing Flowsheets ROM ore In-Situ Leaching Rejects ROM ore ROM ore Ore Sorting or HMS ROM ore Fines Size High Grade Concentrate Dump/Heap Leaching Concentration (Gravity / Flotation) Leach Tailings Lower Grade Concentrate Toowong Leach Acid Alkaline Neutralisation Metal Recovery SX/EW SX/Crystallisation Precipitation Cementation Residue Concentrate - Lower Impurities (e.g. As,Sb) Products - Cathode - Sulphate - Cement - Oxide / Sulphide - Other By-products - Gold/Silver - Cobalt - Molybdenum - Rhenium - Indium - Uranium - Other

6 Copper Processing Flowsheets ROM ore In-Situ Leaching Rejects ROM ore ROM ore Ore Sorting or HMS ROM ore Fines Size High Grade Concentrate Dump/Heap Leaching Concentration (Gravity / Flotation) Leach Tailings Lower Grade Concentrate Toowong Leach Acid Alkaline Neutralisation Metal Recovery SX/EW SX/Crystallisation Precipitation Cementation Residue Concentrate - Lower Impurities (e.g. As,Sb) Products - Cathode - Sulphate - Cement - Oxide / Sulphide - Other By-products - Gold/Silver - Cobalt - Molybdenum - Rhenium - Indium - Uranium - Other

7 Reasons for Copper Ore Sorting Pre-concentrate ore at mine: Removes low-grade fraction that is uneconomic to process. Reduces haulage costs. Reduces grinding energy and flotation reagent costs. Improves metal recoveries. Monitor the mill feed which provides real time data to operators for process optimization. Some of these apply to Heavy Medium Separation also

8 Reasons for Copper Ore Sorting cont. Pre-concentrate feed into high-grade and low-grade stockpiles: Optimize multiple process streams i.e. send ore to either mill, heap leach or smelter. Allows smaller mills to be built or increase capacity of an existing mill. Manage ore blending programs more effectively. For copper heap leach applications, removes gangue acid-consuming (GAC) rocks which reduces acid costs.

9 Sorter General Operation The processer, using pre-determined criteria, decides what ore is accepted and which ore is rejected. Processer drives either valves/flop gates or pneumatic pulses to send the products and rejects to their appropriate bin or conveyor.

10 Ore Sorting Techniques Optical Specific wavelength: X-Ray Transmission (XRT) X-Ray Fluorescence/ Ultraviolet Near infrared Radiometry (Gamma Rays) X-Ray Luminescence High Frequency Electromagnetic Colour

11 XRT examples Industrial Examples: Metallurgical testwork has been completed on copper ores using XRT technology. Sample Mass Distribution (%) Copper Distribution (%) Copper Grade (%) Product Product Head Product Rejects Copper Upgrade A 67% 93% A 60% 87% B 60% 85% C 24% 65% D 56% 88% E 74% 86% F 89% 95%

12 Colour examples Industrial Examples: Scats from a Ball Mill Pink - Carbonates (low Cu) Grey - Bedded Siltstones (high Cu)

13 Colour examples Industrial Examples: Scats from a Ball Mill Red/Pink - Native Copper

14 Examples of GAC Rock Removal Testwork on projects have successfully tested ores with the objective of removing gangue acid consuming (GAC) minerals. These include: Removal of calcites/carbonates in a finished quartz stream. Rejection of GAC minerals from manganese and iron ores. Removal of carbonates from uranium ore to achieve an upgraded concentrate before downstream processing. and with this we believe similar applications could be used on copper ores.

15 Heavy Medium Separation (HMS) Heavy medium separation is the process of separating copper ores by a specific medium (ferro-silicon) density. Testwork on copper ores at a size range of -76 mm + 6 mm and a medium density of 2.8 demonstrated that 49% of the mass can be rejected whilst only losing 14% of copper an upgrade of 169%. Stream Feed (-76 mm +6 mm) +2.8 SG (Product) -2.8 SG (Rejects) Mass Distribution (%) 100% 51% 49% Copper Grade (%) Copper Distribution (%) 100% 86% 14% Copper Upgrade (%) 169%

16 Heavy Medium Separation (HMS) cont. Industrial Examples: Jaguar lead, copper, zinc and silver project in Western Australia, installed a HMS plant in (30 to 35% mass rejected, with 40% upgrade in Feed Grade) Mill performance was improved after completion of the Heavy Media Separation plant (HMS) which removes waste rock from diluted ore and stringer sulphides and increases the mill head grade, reducing processing costs Independence Group 2011/12 Annual Report

17 Toowong Process Determined a clear need with increasing levels of Arsenic in Copper Concentrates Started development work in 2009 Extensive batch and continuous locked cycle testing Tested a range of copper (1.1% to 3.3% As) and nickel concentrates (0.8% As) Leaches Enargite, Tennantite, Tetrahedrite, Gersdorffite Mini Pilot in November 2011 Maxi Pilot in November 2012

18 Maxi Pilot Plant - Overview Ran from 19 th Nov - 21 st Dec 2012 Major $4.5M integrated pilot campaign employing over 60 personnel ~53 kg/day Copper Concentrate treated - 11 days, Toowong Blend - 23 days, Tampakan Composite

19 Maxi Pilot Plant - Flowsheet Water (Condensate) Reagent Recycle Evaporation Sodium Hydroxide (Make-up) Leach Recycle Crystal Feed Concentrate Leach Autoclave Precipitation Bleed Precipitate Residue Treated Concentrate Oxygen Gold + Antimony Precipitate Precipitation Calcium Hydroxide Reagents + Barium Hydroxide + Process Water

20 Maxi Pilot Plant - Operation November 2012 Leach Circuit Concentrate Repulp Circuit

21 Maxi Pilot Plant - Operation November 2012 Leach Residue Filtration PLS Oxidation Autoclave

22 Maxi Pilot Plant - Operation November 2012 Arsenic and Sulphate Precipitation and Filtration Caustic Evaporator

23 Maxi Pilot Plant - Operation Live Process Monitoring (Temperature, Pressure, Mass Flow, Tank Level, Current Draw)

24 Maxi Pilot Plant - Operation Key results: Toowong Blend Tampakan Concentrate Units Feed Product Extracted Feed Product Extracted As % % % Sb % % % 0.09% arsenic in treated concentrate over the final 10 days of testing Tampakan concentrate (average) >90% arsenic extraction over the final 10 days of testing (average) Also significant removable of antimony, mercury and tin

25 Toowong Funding and IP Core Resources and Xstrata (Now Glencore) Funded Development Provisional Patent lodged in Oct 2011 Glencore currently owns IP, (since has reverted to Core) Core Resources has rights to use and licence to third parties any patents granted

26 Albion Process Leach Flowsheets ROM ore ROM ore Fines Size Coarse Concentration (Gravity / Flotation) High Grade Concentrate Tailings Lower Grade Concentrate Albion Leach Neutralisation Concentrate - Lower Impurities (e.g. As,Sb) Metal Recovery SX/EW SX/Crystallisation Precipitation Cementation Residue Products - Cathode - Sulphate - Cement - Oxide / Sulphide - Other By-products - Gold/Silver - Cobalt - Molybdenum - Rhenium - Indium - Uranium - Other

27 Albion Process Leach Flowsheets Opportunities to Add Value Alternative products By-products In-situ acid production reduce acid cost Use of alternative neutralising materials reduce neutralising cost Impurity removal Integrated flowsheets Additional metal recovery Key drivers

28 Albion Process Leach Product Options Copper Cathode Larger scale projects Low/moderate power costs Remote / high transport costs Copper Sulphate Premium over metal Smaller scale projects Power costs higher Local demand zinc flotation, fertilizer plant, feedlot Cu 2+ + Fe = Fe 2+ + Cu Other (Cement, Copper Sulphide, Copper Oxide) Copper cement concentrates or low cost scrap iron available Intermediate product market nearby or integrated flowsheet

29 Impurity Removal Many large undeveloped copper deposits have significant impurity issues. Salobo, Brazil La Granja, Peru Tampakan, Philippines Nena, PNG Many other South American Copper Projects High Fluorine High Arsenic High Arsenic High Arsenic High Arsenic

30 Concentrate and Leaching Synergies Case Study Normal grade concentrate for sale vs. High grade concentrate for sale plus Low grade concentrate to leaching

31 Copper Recovery 40 Copper Grade/Recovery 35 Liberated Chalcopyrite Copper Grade - % Cu Target Concentrate Grade - 25% Cu Perfect Separation Max. Theoretical Recovery Copper Recovery %

32 Copper Recovery 40 Copper Grade/Recovery Copper Grade - % Cu Liberated Chalcopyrite Plant Separation Liberated Gangue recovered by "Entrainment" or "True" Flotation Target Concentrate Grade - 25% Cu Perfect Separation Plant Recovery Copper Recovery %

33 Copper Recovery Case Study 40 Copper Grade/Recovery 35 Liberated Chalcopyrite Copper Grade - % Cu Concentrate for Sale Target Concentrate Grade - 30% Cu 30% Recovery to Lower Grade Copper Concentrate - 7.5% Cu 15 Concentrate for Leaching Copper Recovery %

34 Case Study - Project A Copper/Cobalt concentrate recovered from tailings of existing copper operation Grade of concentrate - 2.2% Cu and 0.28% Co Prefeasibility testing followed by Albion Process Pilot Plant run Pilot Results on ~600 kg of concentrate over 24 day run 94% Copper extraction 81% Cobalt extraction Downstream cobalt recovery testwork now being conducted Project Capex in the order of $80M

35 Case Study - Project B Copper/Gold concentrate recovered from tailings of existing copper operation (additional 17% Cu and 25% Au recovery) Grade of concentrate - 2.4% Cu and 1.5 g/t Au Tonnes of concentrate 640,000 tpa, containing ~15,000 tpa Cu and ~30,000 oz Au/y Scoping Study results 93% Copper recovery 85% Gold recovery Project Capex in the order of US$200M

36 Summary Ore sorting can be used in copper processing for: Upgrading ore to reduce haulage, reduce processing costs and improve the overall capital cost position along with; Removing GAC minerals in heap leach applications. Heavy Medium Separation can be used on some copper ores to improve project economics. Toowong Process has demonstrated that it is an option for removing impurities from dirty copper concentrates. Albion Process has a role in improving overall project economics, by improving recovery of copper from certain more difficult projects, along with dealing with impurities.

37 Independent Company Eberhard Krause - HydroMet Solutions Inc. Initially, HS was somewhat concerned that Barrick had chosen Core, rather than an independent engineering firm, to carry out this pre-feasibility study (PFS), because one might have expected a positive bias towards the Albion Process option... As was demonstrated by the outcome of the pre-feasibility study, which looked at three potential process options (Albion, Roaster and a hybrid roaster/albion Process), such worries were unfounded

38 Questions?